The present invention relates to an optical system for merging a first and a second partial image beam, each proceeding from a specimen, into a resultant image beam Such systems are used in particular in optical instruments for the examination of multiple prepared specimens such as, for example, comparison microscopes or comparison macroscopes.
When comparative examinations are carried out, the image of a first sample is usually compared with the image of a second sample. Comparison microscopes and comparison macroscopes in which partial image beams deriving from two objectives can be combined, by means of an optical system such as, for example, a comparison bridge, into one resultant image beam that can be viewed by the user, are known for carrying out such examinations. A variety of possibilities for depiction usually exist in this context, the resultant image being generated from the partial images by corresponding setting of stops; a mixing or superimposition of the respective partial images, or partial side-by-side placement or juxtaposition of portions of the partial images, is possible in this context.
An optical system of the generic kind is described in DE 1 623 228 A. The comparison bridge that is described comprises two movable stop arrangements in order to generate the image configurations described above. For this purpose, the user must operate with both hands, during the examination, rotary knobs located approximately at shoulder height; this proves to be uncomfortable and difficult to handle. In particular, the use of both hands during operation is necessary, so that no other activities can be performed simultaneously.
Other embodiments of comparison bridges that can be operated with one hand are known, for example from DE 938271 A. These comparison bridges have the disadvantage, however, that the various image configurations described above cannot be displayed. In particular, variable juxtaposition of subregions of an image, and displacement of the separating line, are not possible.
In order to improve the mechanical comparison bridges just described, motorized configurations have been developed that offer convenient usability for a plurality of different image configurations. These motorized embodiments have, however, the disadvantage of considerable additional design complexity and therefore also of increased acquisition and maintenance costs.
It is therefore desirable to provide an optical system according to the preamble of claim 1 that, with little design complexity and without motorization, can be operated by the user as easily and conveniently as possible and nevertheless enables a variety of image configurations.
The invention provides an optical system for merging a first and a second partial image beam into a resultant image beam in an optical instrument for the examination of prepared specimens, wherein the first and second partial image beam both emanate from the specimen, said optical system comprising a stop arrangement provided with: at least one first movable stop element for the first partial image beam; at least one second movable stop element for the first partial image beam; wherein said first and second stop elements each comprise at least one stop region adapted to be brought into a working position with the first or second partial image beam by movement of the respective first or second stop element in order to modify the areal proportion of the respective first or second partial image beam in the resultant image beam; and a movably arranged connecting means for connecting the two stop elements, said connecting means being adapted to modify the respective areal proportions of the partial image beams in the resultant image beam by movement of the connecting means.
An optical system according to the present invention for merging a first and a second partial image beam, each proceeding from a specimen, into a resultant image beam can be utilized in particular in an optical instrument for the (for example, forensic) examination of prepared specimens, for example a comparison microscope or a comparison macroscope. The optical system comprises a stop arrangement that comprises, for the first and for the second partial image beam, a respective movable stop element each having one or more stop regions, wherein at least one stop region can be brought, by movement of the stop element, into a working position with a partial image beam in order to modify the areal proportion of the respective partial image beam in the resultant image beam, the stop arrangement comprising a movably arranged connecting means for connecting the two stop elements. The respective areal proportions of the partial image beams in the resultant image beam are modifiable or settable by movement of the connecting means. A stop element is movable preferably within an image plane, for example an intermediate image plane, or into an image plane.